1. Field of the Invention
The present invention relates to a voltage regulator, and in particular to a linear regulator with fast response to the condition of a load.
2. Description of the Related Art
A typical example of linear regulators is the low drop-out (LDO) circuit. FIG. 1 shows a conventional LDO circuit 10, which includes a transconductor gm that controls a power transistor P0 to turn on or turn off according to a comparison between a feedback signal FB and a reference voltage Vref, so that a supply voltage Vcc Is converted to an output voltage Vout.
Such regulator has a drawback that it can not respond in time when its load changes from heavy to light or no load; its output is unstable under such circumstance, that is, the output overshoot will last a long time until it is relieved, and it will consume power unnecessarily.
In view of the above, a linear regulator with fast response to the condition of a load is desired.